Strip of fasteners and loader of such a strip for equipment for driving such fasteners

ABSTRACT

The strip comprises fasteners ( 1 ), each having a shank ( 2 ) which is pointed at one end ( 4 ) and bears a head ( 3 ) at the other end, these fasteners being respectively engaged by their shanks ( 2 ) in guide and damping blocks joined together in a string ( 8 ). The strip comprises a second guide string ( 9 ).  
     The loader comprises a chamber ( 13 ) for accommodating the fastener heads ( 3 ), a chamber ( 14; 13 ) for accommodating the first string ( 8 ) and a chamber ( 14; 15 ) for accommodating the second string ( 9 ), the chambers being connected in pairs by hollow shafts ( 16, 17 ) that accommodate the fastener shanks ( 2 ).

[0001] The field of the invention is that of the fastening of elementsof the nail or wall plug type, comprising a shank with a rear head and apointed front end.

[0002] In general, for this purpose use is made of indirectly firedanchoring equipment and a fastener is introduced into the barrel eitherby hand, from the front, into the plug guide of the equipment, orautomatically using a loader.

[0003] In order that, as it is being driven along the barrel of theequipment, after firing and before being introduced into the receivingmaterial, the fastener remains perfectly coaxial with the barrel, doesnot tip with respect to the axis and therefore remains correctly guided,it has already been proposed for a guide washer or guide block to beslipped onto the shank of the fastener. In fact, two guide washersspaced apart along the shank or one guide block of sufficient axiallength to ensure good cohesion between the nail and its guide block havealready been proposed.

[0004] It will be noted that feeding fasteners with guide washers intothe barrel of the equipment can be performed only by hand, or, at apinch, from a dispenser, whereas fasteners with guide blocks can beoffered up in strip form with their blocks back to back in a string, thestrip being mounted in a loader with a return spring so that when theloader is mounted on the equipment, it pushes the strip and introduces aguide block into the barrel prior to each firing. A string of guideblocks is described, for example, in patent EP 0 502 667.

[0005] It will also be noted that with fasteners in strip form, aftereach firing, the block of the fastener that is to be driven is separatedfrom the adjacent block by shearing by the flyweight of the equipmentand then, at the moment that the fastener is driven into the receivingmaterial, the block acts as a damper and as a washer.

[0006] The applicant has noticed that one block was not always enough toensure correct guidance of the fastener when it is long, and this is whythis invention is proposed here thereby.

[0007] The invention relates first of all to a strip of fasteners eachhaving a shank which is pointed at one end and bears a head at the otherend, these fasteners being respectively engaged by their shanks in guideand damping blocks joined together in a string, characterized in that ithas a second guide string.

[0008] The second guide string may consist of guide washers joinedtogether like the guide and damping blocks of the first string, but thesecond string may also consist of guide and damping blocks.

[0009] The two strings are not necessarily made of the same material.

[0010] In the case of a strip of short fasteners, the two strings may beback to back on the shanks of the fasteners.

[0011] In the case of long fasteners, the two strings are advantageouslyspaced apart along the shanks of the fasteners.

[0012] The invention also relates to a loader of a strip of fastenersfor equipment for driving such fasteners each having a shank and a headengaged respectively by their shanks in first guide and damping blocksjoined together in a first string and in second guide means joined toform a second string, the loader comprising a chamber for accommodatingthe fastener heads, a chamber for accommodating the first string and achamber for accommodating the second string, the chambers beingconnected in pairs by hollow shafts for accommodating the fastenershanks.

[0013] Advantageously, the chamber furthest from the chamber foraccommodating the shank heads opens into a third hollow shaft thataccommodates fastener shank portions for fasteners with long shanks.

[0014] As a preference, the chamber for accommodating fastener heads isdesigned also to accommodate one of the two strings, in the case offasteners with long shanks guided at two points spaced apart.

[0015] As a preference also, there is an intermediate chamber designedto accommodate the two strings in the case of fasteners with shortshanks engaged in two strings back to back.

[0016] The invention will be better understood with the aid of thefollowing description of several forms of embodiment of the strip offasteners and of the strip loader, with reference to the appendeddrawing, in which

[0017]FIG. 1 is a plan view of the strip, the long fasteners beingengaged in the guide and damping blocks of two strings spaced apart;

[0018]FIG. 2 is a profile view of the strip of FIG. 1;

[0019]FIG. 3 is a plan view of the strip, similar to that of FIG. 1, butwith the two strings back to back;

[0020]FIG. 4 is a profile view of the strip of FIG. 3;

[0021]FIG. 5 is a plan view of the strip, similar to that of FIG. 1, theblocks of the two strings being of a simplified form, with guide blocksthat have no blow-out portions;

[0022]FIG. 6 is a profile view of the strip of FIG. 5;

[0023]FIG. 7 is a view in section of the loader of the invention, with astrip of short fasteners;

[0024]FIG. 8 is a view in section on VIII-VIII of FIG. 7;

[0025]FIG. 9 is a view in section on IX-IX of FIG. 7;

[0026]FIG. 10 is a view in section of the loader of the invention, witha strip of long fasteners;

[0027]FIG. 11 is a view in section on XI-XI of FIG. 10, and

[0028]FIG. 12 is a view in section on XII-XII of FIG. 10.

[0029] The strip of fasteners in FIGS. 1 and 2 therefore comprisesfasteners 1, with a shank 2, a head 3 and a pointed end 4, each of thefasteners 1 being engaged in two guide and damping blocks 5, 6 with ablow-out portion 7, as described, for example, in EP 0 502 667. Theblocks 5, 6 are spaced apart along the shank 2. The blocks 5 closest tothe heads 3 are connected to one another in a first string 8, the blocks6 closest to the pointed ends 4 being connected up to form a secondstring 9 spaced away from the first one.

[0030] The strip of fasteners in FIGS. 3 and 4 is practically identicalto the previous one. The only difference lies in the fact that the twostrings 8′, 9′ are back to back. These strings are slipped over the samefasteners 1, of the same length, as those in the previous example;however, this arrangement of two back-to-back strings is more suitableto short fasteners.

[0031] The strip of fasteners in FIGS. 5 and 6 is also practicallyidentical to the previous ones. The only difference compared with thestrip in the first FIGS. 1 and 2 lies in the fact that the two strings8″, 9″ slipped over the same fasteners 1, are in simplified form, withguide blocks 5″, 6″ with no blow-out portion.

[0032] With reference to FIGS. 7-12, a loader for a strip of fastenersand which can be mounted in the conventional way on equipment fordriving and fixing these elements, comprising a barrel 10 in which afly-weight 11 for driving a fastener 1 is slideably mounted, will now bedescribed. The loader, as far as the automatic advance of the strip offasteners and therefore the loading of the barrel is concerned, isarranged in the conventional way, with a return spring, not depicted, topush the strip in the direction of the axis 12 of the barrel andintroduce a fastener with its two guide blocks, into the barrel.

[0033] The loader comprises three parallelepipedal chambers 13, 14 and15 running longitudinally, that is to say in the direction of travel ofthe strip through the loader; these three chambers are connected inpairs by two hollow shafts 16, 17 that accommodate shank portions of thefasteners, the accommodating chamber 15 closest to the mouth 18 of thebarrel 10 opening into a third hollow shaft 19. The width of thechambers is only very slightly greater than the diameter (or width) ofthe guide blocks 5, 6, while the width of the hollow shafts is only veryslightly greater than the diameter of the shanks 2 of the fasteners 1.

[0034] The heads 3 of the fasteners 1 are accommodated in the firstchamber 13 furthest from the mouth 18 of the barrel 10. In the case offasteners with short shanks, such as those in FIGS. 7-9, the guideblocks 5, 6 of the two strings back to back are accommodated in theintermediate chamber 14, the points 4 of the shanks 2 of the fastenersextending into the hollow shaft 17 connecting the intermediate chamber14 and the third chamber 15 closest to the barrel mouth 18.

[0035] In the case of fasteners 1 with long shanks, such as those ofFIGS. 10-12, the two strings 8, 9 of guide blocks 5, 6 being spacedapart along the shanks 2 of the fasteners 1, the first string 8 of theblocks 5 closest to the heads 3 is accommodated in the same chamber 13as the heads 3. The second string 9 of the blocks 6 is accommodated inthe third chamber 15, the intermediate second chamber 14 being empty ofblocks and having only fastener shank portions 2 passing through it, theends 4 of which portions extend into the third hollow shaft 19. It willhave been noted that it is for reasons of simplicity that the referencesof the fasteners used in FIGS. 7-9 have been repeated in FIGS. 10-12.

1. Strip of fasteners (1) each having a shank (2) which is pointed atone end (4) and bears a head (3) at the other end, these fasteners beingrespectively engaged by their shanks (2) in guide and damping blocksjoined together in a string (8) , characterized in that it has a secondguide string (9).
 2. Strip of fasteners according to claim 1, in whichthe second guide string consists of guide washers joined together. 3.Strip of fasteners according to claim 1, in which the second string (9)consists of guide and damping blocks (6).
 4. Strip of fastenersaccording to claim 3, in which the fasteners (1) are short and the twostrings (8′, 9′) are back to back on the shanks (2) of the fasteners(1).
 5. Strip of fasteners according to claim 3, in which the fasteners(1) are long and the two strings (8, 9; 8″, 9″) are spaced apart alongthe shanks (2) of the fasteners (1).
 6. Loader of a strip of fastenersfor equipment for driving such fasteners each having a shank (2) and ahead (3) engaged respectively by their shanks (2) in first guide anddamping blocks (5) joined together in a first string (8) and in secondguide means (6) joined to form a second string (9), the loadercomprising a chamber (13) for accommodating the fastener heads (3), achamber (14; 13) for accommodating the first string (8) and a chamber(14; 15) for accommodating the second string (9), the chambers beingconnected in pairs by hollow shafts (16, 17) for accommodating thefastener shanks (2).
 7. Loader according to claim 6, in which thechamber (15) furthest from the chamber (13) for accommodating the shankheads (3) opens into a third hollow shaft (19) that accommodatesfastener shank portions (4) for fasteners (1) with long shanks (2). 8.Loader according to one of claims 6 and 7, in which the chamber (13) foraccommodating fastener heads (3) is designed also to accommodate one (8)of the two strings, in the case of fasteners with long shanks (2) guidedat two points spaced apart (8).
 9. Loader according to one of claims 6to 8, in which there is an intermediate chamber (14) designed toaccommodate the two strings (8, 9) in the case of fasteners (1) withshort shanks (2) engaged in two strings (8, 9) back to back.